JPH07188136A - Method for producing N-alkylbenzoylformamide - Google Patents

Abstract

(57) [Summary] [Object] To provide an industrially valuable production method in the production of N-alkylbenzoylformic acid amides, which are intermediates for the production of agricultural drugs, dyes and the like. In a method for producing an N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with an alkyl isocyanide, the reaction mixture obtained after the reaction is treated with an aqueous solution of a metal alkali without lowering the yield. Very high purity N-alkylbenzoylformic acid amides can be produced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing N-alkylbenzoylformic acid amides. More specifically, it relates to an improved process for the preparation of N-alkylbenzoylformamides from benzoyl chlorides and alkyl isocyanides.

[0002]

BACKGROUND OF THE INVENTION N-Alkylbenzoylformic acid amide, which is the object compound of the present invention, is an important compound as an intermediate for the production of agricultural chemicals, pharmaceuticals and the like. In particular, JP-A-3-2462
It is important as an intermediate in the production of an alkoxyiminoacetic acid amide compound which is an agricultural bactericidal agent shown in Japanese Patent No. 68 or an alkoxyiminoacetic acid ester compound which is an agricultural bactericidal agent shown in JP-A-63-30463. It is a compound. Conventionally, as a method for producing this N-alkylbenzoylformate, a method for producing N-alkylbenzoylformate by reacting benzoyl chlorides with alkylisocyanide has been used. On the other hand, a method is known in which benzoyl chlorides are reacted with a metal cyanide to give benzoyl nitrites, which are then hydrolyzed and alkylated to produce an N-alkylbenzoylformamide, but the steps are relatively complicated. The method using the above-mentioned benzoyl chlorides and alkyl isocyanide is frequently used for.

However, it is known that N-formyl-N-alkylbenzoylimide and benzoic acid are by-produced in the method for producing N-alkylbenzoylformic acid amide by reacting benzoyl chloride with alkylisocyanide. Therefore, it is difficult to easily produce an N-alkylbenzoylformic acid amide with high yield and high quality, and a purification step such as silica gel column chromatography or recrystallization is required, which inevitably complicates the operation. . That is, in the method for producing N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with alkyl isocyanide, the N-formyl-N
-A method for producing an N-alkylbenzoylformic acid amide in high yield while suppressing by-products of benzoylimide and benzoic acids has been desired.

[0004]

The present inventors have found an improved production method of the prior art which solves these problems and produces the desired N-alkylbenzoylformic acid amide in high yield and high quality. There is. However, in order to obtain an extremely high-purity N-alkylbenzoylformic acid amide, further purification operations such as recrystallization or column chromatography are required. An object of the present invention is to provide a method for producing a high-purity N-alkylbenzoylformic acid amide which is industrially more efficient than the prior art from these matters.

[0005]

In the method for producing N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with alkylisocyanide, the present inventor has further improved productivity and aimed to obtain N-alkylbenzoylformic acid. As a result of extensive studies on a method for producing an amide with high yield and high quality, a method for producing an N-alkylbenzoylformic acid amide that solves this problem has been found, and the present invention has been completed.

That is, in the method for producing an N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with an alkyl isocyanide, the reaction mixture obtained after the reaction is treated with an aqueous alkali metal solution to obtain the desired N-alkyl amide.
The present inventors have completed the present invention by finding that alkylbenzoylformic acid amide can be produced in high purity without lowering the yield.

That is, the method of the present invention comprises reacting benzoyl chlorides with an alkyl isocyanide to produce an N-alkylbenzoylformic acid amide and producing an N-alkylbenzoylformic acid amide with high yield. This is a method for producing a desired N-alkylbenzoylformamide. Specifically, the present invention relates to a method for producing an N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with an alkyl isocyanide,
A method for producing an N-alkylbenzoylformic acid amide, which comprises reacting benzoyl chlorides with an alkyl isocyanide, and treating the resulting reaction mixture with an aqueous metal alkali solution after the reaction.

The method of the present invention will be described below. The benzoyl chlorides used in the method of the present invention are benzoyl chlorides in which the benzene nucleus may be unsubstituted or substituted. Specifically, 2-phenoxybenzoyl chloride, 2- (4-methylphenoxy) benzoyl chloride, 2- (3-methylphenoxy) benzoyl chloride, 2- (3,4-dimethylphenoxy) benzoyl chloride, 2- (4 -Ethylphenoxy) benzoyl chloride, 2- (3-ethylphenoxy) benzoyl chloride, 2- (4-methoxyphenoxy) benzoyl chloride, 2- (3-methoxyphenoxy) benzoyl chloride, 2- (4-chlorophenoxy) benzoyl chloride , 2- (3-chlorophenoxy) benzoyl chloride, 2- (phenoxymethyl) benzoyl chloride, 2
Examples thereof include-(2-chlorophenoxymethyl) benzoyl chloride and 2- (2,5-dichlorophenoxymethyl) benzoyl chloride. However,
The benzoyl chlorides are not limited by the compounds listed here.

The alkyl isocyanide used in the method of the present invention is methyl isocyanide having an alkyl group of 1 to 3 carbon atoms, ethyl isocyanide, n-propyl isocyanide, isopropyl isocyanide or the like. The amount of the benzoyl chloride and the alkyl isocyanide used is such that the alkyl isocyanide is usually in the range of 0.5 to 10 molar equivalents, and preferably 1 to 5 molar equivalents relative to the benzoyl chloride. It is a range.

In the method of the present invention, a predetermined amount of benzoyl chloride is charged into alkylisocyanide in the presence of an organic solvent inert to the raw material and the product or without the solvent and the reaction is carried out. The order of charging the raw materials is not limited to this,
Any order is acceptable. The reaction temperature is usually in the range of 0 ° C to the boiling point of the organic solvent, preferably 0 ° C to 80 ° C.
Is the range. The reaction time is not uniquely determined by the reaction temperature and the concentration, but usually the reaction is completed within 5 hours. Then, a predetermined amount of an aqueous hydrochloric acid solution and a water-soluble organic solvent such as acetone is added, and the mixture is added for 1 to 5 hours to 0 to 100
React at ℃ to obtain a reaction mixture.

The reaction mixture obtained by the above reaction is treated with an aqueous metal alkali solution. In this treatment, when a water-soluble organic solvent is used as a reaction solvent or a solvent-free organic solvent, a poorly water-soluble organic solvent is newly added to the reaction mixture.
The reaction mixture is washed with a metallic alkali aqueous solution, liquid separation is performed, and then water washing is performed to distill off the solvent. If the reaction mixture is not treated with an aqueous alkali metal solution, the quality of the N-alkylbenzoylformic acid amide obtained is reduced, but the quality is improved by this treatment. Particularly when the reaction system contains water, the purity is remarkably lowered, which is not preferable.

The metal alkali used in the method of the present invention is not particularly limited as long as it has a high solubility in water. Industrially, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, or potassium hydrogencarbonate is often used in consideration of economic aspects. The concentration of the aqueous alkali metal solution is in the range of 0.1 to 20% by weight. If the concentration of the aqueous alkaline metal solution is less than 0.1% by weight, the cleaning effect is small and the purity of the N-alkylbenzoylformic acid amide in the obtained product is low. On the other hand, if it exceeds 20% by weight, the alkali content remains in the organic solution after washing, and it is necessary to wash with excess water, which complicates the operation and is not industrially preferable.

In the method of the present invention, the processing temperature is 80.
The hydrolysis reaction of the N-alkylbenzoylformic acid amide can be suppressed at a temperature of not higher than 0 ° C., and high purification can be performed without lowering the yield. However, if the treatment temperature exceeds 80 ° C., the hydrolysis reaction of the N-alkylbenzoylformic acid amide proceeds and the yield is reduced, which is not preferable.

Thus, according to the method of the present invention, a pesticide,
The N-alkylbenzoylformic acid amide, which is an important compound as an intermediate for the production of medicines, etc., can be prepared by extracting the reaction mixture with an organic solvent, treating it with an aqueous metal alkali solution, and distilling off the solvent without performing a complicated purification operation. It can be isolated in high yield and quality. Therefore, the method of the present invention is a method for producing an N-alkylbenzoylformic acid amide having an extremely high industrial value.

[0015]

The present invention will be further described below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. [Example 1] 0.43 g (10.5) of methyl isocyanide
mmol) to 2-phenoxybenzoyl chloride 2.3.
2 g (10.0 mmol) was added at 15 ° C., the temperature was raised to 60 ° C., and the mixture was stirred for 3 hours. Concentrate under reduced pressure as it is, and acetone 5
g and 3 g of 18% hydrochloric acid were added, and the mixture was stirred at 60 ° C. for 2 hours.
Extraction with 20 g of chloroform, washing with 20 g of 10% aqueous sodium carbonate solution, washing with water, and evaporation of the solvent gave 2.29 g of the target compound, N-methyl-2-phenoxybenzoylformic acid amide. The composition was as follows, and the yield in terms of purity was 89.0%. N-methyl-2-phenoxybenzoylformic acid amide 99.0% N-formyl-N-methyl-2-phenoxybenzoylimide 0.1%

[Example 2] 1 as an aqueous solution of metal alkali
When carried out in the same manner as in Example 1 using a 0% aqueous potassium carbonate solution, 2.27 g of the target compound, N-methyl-2-phenoxybenzoylformic acid amide, was obtained. Purity conversion yield is 8
It was 8.1%. N-methyl-2-phenoxybenzoylformic acid amide 99.1% N-formyl-N-methyl-2-phenoxybenzoylimide 0.1%

[Embodiment 3] 2 as an aqueous alkali metal solution
% Aqueous potassium hydroxide solution to carry out the same procedure as in Example 1 to obtain 2.17 g of the target compound, N-methyl-2-phenoxybenzoylformic acid amide. The yield in terms of purity based on 2-phenoxybenzoyl chloride was 84.4%. N-methyl-2-phenoxybenzoylformic acid amide 99.3% N-formyl-N-methyl-2-phenoxybenzoylimide 0.1%

Example 4 Ethyl isocyanide 0.58
Using g (10.5 mmol) in the same manner as in Example 1, 2.49 g of the target compound, N-ethyl-2-phenoxybenzoylformic acid amide, was obtained. The yield in terms of purity based on 2-phenoxybenzoyl chloride was 90.7%. N-ethyl-2-phenoxybenzoylformic acid amide 97.9% N-formyl-N-ethyl-2-phenoxybenzoylimide 0.3%

[Example 5] 3.16 g (10.%) of 2- (2,5-dichlorophenoxymethyl) benzoyl chloride
Was performed in the same manner as in Example 1 to obtain 2.93 g of the target compound, N-methyl-2- (2,5-dichlorophenoxymethyl) benzoylformate.
The yield in terms of purity based on 2- (2,5-dichlorophenoxymethyl) benzoyl chloride was 86.7%. N-methyl-2- (2,5-dichlorophenoxymethyl) benzoyl formate 99.8% N-formyl-N-methyl-2- (2,5-dichlorophenoxymethyl) benzoyl imide 0.1%

[Comparative Example] When the same procedure as in Example 1 was carried out, except that the treatment with an aqueous alkali metal solution was not carried out and only washing with water was carried out, 2.40 g of the objective compound, N-methyl-2-phenoxybenzoylformic acid amide, was obtained. The yield in terms of purity was 89.4%. N-methyl-2-phenoxybenzoylformic acid amide 95.1% N-formyl-N-methyl-2-phenoxybenzoylimide 0.3%

[0021]

INDUSTRIAL APPLICABILITY According to the method of the present invention, extremely high-purity N-alkylbenzoylformamide can be produced without lowering the yield. Therefore, the present invention is an industrially efficient method.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuichi Mita 30 Asamu-cho, Omuta-shi, Fukuoka Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. A method for producing an N-alkylbenzoylformic acid amide by reacting benzoyl chlorides with an alkyl isocyanide, wherein the reaction mixture obtained after the reaction is treated with an aqueous alkali metal solution. Method for producing formic acid amide. 2. The aqueous metal alkali solution is sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,
The method according to claim 1, which is an aqueous solution of sodium hydrogen carbonate or potassium hydrogen carbonate.